<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8" />
  <meta http-equiv="X-UA-Compatible" content="IE=edge" />
  <meta name="viewport" content="width=device-width, initial-scale=1.0" />
  <title>Document</title>
  <script src="https://cdn.jsdelivr.net/npm/vue@2.6.10/dist/vue.js"></script>
</head>

<body>
  <div id="app">
    <h1>新闻</h1>
    <ul>
      <!-- 
        需要遍历哪一个元素,就在哪一个元素上使用v-for指令
        遍历可以使用in 也可以使用of
        遍历中item和index会作为`局部变量`在当前被遍历的元素上及内部直接使用
      -->
      
      <button @click="news.unshift({id:'004',content:'新增'})">add</button>
      <li v-for="item,index of news" :key="item.id">
        <p>编号:{{item.id}}</p>
        <p>{{item.content}}</p>
      </li>
    </ul>
  </div>
  <script>
    Vue.config.productionTip = false;

    const vm = new Vue({
      el: "#app",
      data () {
        return {
          news: [
            { id: "001", content: "今天我们......" },
            { id: "002", content: "明天要下雨......" },
            { id: "003", content: "后天要放假......" },
          ],
        };
      },
    });
  </script>
</body>

</html>